LVM - Logical Volumes
Logical Volumes are used to store your file systems. You create
logical volumes in
server# lvcreate -L 1G -n VS-SSH RAID
creates the logical volume "VS-SSH" in the volume group "RAID" with a size of 1 gigabyte.
There are two forms of the
lvrename command that will rename a logical volume.
server# lvrename /dev/RAID/VS-SSH /dev/RAID/SSH-VSERVER
server# lvrename RAID VS-SSH SSH-VSERVER
will rename the VS-SSH logical volume in the RAID volume group to SSH-VSERVER.
You remove the logical volume
VSbzfsbroken as follows:
root@vserver:/etc/vservers# lvremove /dev/RAID/VSbzfsbroken Do you really want to remove active logical volume "VSbzfsbroken"? [y/n]: y Logical volume "VSbzfsbroken" successfully removed root@vserver:/etc/vservers#
I have a samba vserver on my vserver box. It's been set up for ages. My vservers are LVM on software RAID-1.
I have 2 disks (different sizes) both with a 150GB partition setup as software RAID-1.
On that 150GB partition I've created an LVM physical volume called RAID.
So now I have a 150GB physical volume (disk) with 150GB of free space. I created logical volumes in that for each of my vserver root partitions. This makes each vserver root partition backed by RAID-1 so if a drive fails they still work.
The samba server was set up as 2GB ages ago and it's been running great with about 40% free space.
I need to move more data to that vserver and it doesn't fit.
reports that there's 25GB of unallocated space on my RAID volume. So
I just shut down my samba vserver, resize the LVM partition for the
samba root partition from 2GB to 6GB, and resize the ext3 partition as
# vserver samba stop # umount /var/lib/vservers/samba/ # lvresize -L 6G /dev/RAID/VSsamba # e2fsck -f /dev/RAID/VSsamba # resize2fs /dev/RAID/VSsamba # mount /dev/RAID/VSsamba # vserver samba start # vserver samba enter root@samba:/# df -h Filesystem Size Used Avail Use% Mounted on /dev/hdv1 6.0G 1002M 4.7G 18% / none 16M 0 16M 0% /tmp smaug:/backups 202G 109G 84G 57% /backups /dev/mapper/RAID-PHOTOS 50G 28G 19G 60% /photos
and I'm done. That takes all of about 1 minute to do.
Now my samba vserver is up with 6GB of root file space and I have 21.76GB left of free space on my RAID volume which I can allocate other places I may need it in the future.
I love LVM!
I allocate as little space as I think I need and leave free space in the physical volume that I can use part of later for any volume that needs to expand. This way I don't have to know up front how much space I need to set up (and get it wrong).